By Peter Beaumont, foreign affairs editor
Iran's efforts to produce highly enriched uranium, the material used to make nuclear bombs, are in chaos and the country is still years from mastering the required technology.
Iran's uranium enrichment programme has been plagued by constant technical problems, lack of access to outside technology and knowhow, and a failure to master the complex production-engineering processes involved. The country denies developing weapons, saying its pursuit of uranium enrichment is for energy purposes.
Despite Iran being presented as an urgent threat to nuclear non-proliferation and regional and world peace - in particular by an increasingly bellicose Israel and its closest ally, the US - a number of Western diplomats and technical experts close to the Iranian programme have told The Observer it is archaic, prone to breakdown and lacks the materials for industrial-scale production.
The disclosures come as Iran has told the UN nuclear watchdog, the International Atomic Energy Agency [IAEA], that it plans to install a new 'cascade' of 3,000 high-speed centrifuges at its controversial underground facility at Natanz in central Iran next month.
The centrifuges were supposed to have been installed almost a year ago and many experts are extremely doubtful that Iran has yet mastered the skills to install and run it. Instead, they argue, the 'installation' will more probably be about propaganda than reality.
The detailed descriptions of Iran's problems in enriching more than a few grams of uranium using high-speed centrifuges - 50kg is required for two nuclear devices - comes in stark contrast to the apocalyptic picture being painted of Iran's imminent acquisition of a nuclear weapon with which to attack Israel. Instead, say experts, the break-up of the nuclear smuggling organisation of the Pakistani scientist Abdul Qadheer Khan has massively set back an Iran heavily dependent on his network.
A key case in point is that Tehran originally procured the extremely high-quality bearings required for the centrifuges' carbon-fibre 'top rotors' - spinning dishes within the machines - from foreign companies in Malaysia.
With that source closed down two years ago, Iran is making the bearings itself with only limited success. It is the repeated failure of these crucial bearings, say some sources, that has been one of the programme's biggest setbacks.
Iran is also believed to be critically short of key materials for producing a centrifuge production line to highly enrich uranium - in particular the so-called maraging steel, able to be used at high temperatures and under high stress without deforming - and specialist carbon fibre products. In this light, say some experts, its insistence that it will install 3,000 new centrifuges at the underground Natanz facility in the coming months is as much about domestic PR as reality.
The growing recognition, in expert circles at least, of how far Iran is from mastering centrifuge technology was underlined on Friday by comments by the head of the IAEA, whose inspectors have been attempting to monitor the Iranian nuclear programme.
Talking to the World Economic Forum at Davos, Switzerland, Mohamed El Baradei appealed for all sides to take a 'time out' under which Iranian enrichment and UN sanctions would be suspended simultaneously, adding that the point at which Iran is able to produce a nuclear weapon is at least half a decade away. In pointed comments aimed at the US and Israel, the Nobel Peace prize winner warned that an attack on Iran would have 'catastrophic consequences'.
Yet some involved in the increasingly aggressive standoff over Iran fear tensions will reach snapping point between March and June this year, with a likely scenario being Israeli air strikes on symbolic Iranian nuclear plants.
The sense of imminent crisis has been driven by statements from Israel, not least from Prime Minister Ehud Olmert, who has insisted that 2007 is make-or-break time over Iran's nuclear programme.
Recent months have seen leaks and background briefings reminiscent of the softening up of public opinion for the war against Iraq which have presented a series of allegations regarding Iran's meddling in Iraq and Lebanon, the 'genocidal' intentions of its president, Mahmoud Ahmadinejad, and its 'connections' with North Korea's nuclear weapons programme.
It also emerged last week in the Israeli media that the country's private diplomatic efforts to convince the world of the need for tough action on Iran were being co-ordinated by Meir Dagan, the head of Israel's foreign intelligence service, Mossad.
The escalating sense of crisis is being driven by two imminent events, the 'installation' of 3,000 centrifuges at Natanz and the scheduled delivery of fuel from Russia for Iran's Busheyr civil nuclear reactor, due to start up this autumn. Both are regarded as potential trigger points for an Israeli attack.
'The reality is that they have got to the stage where they can run a small experimental centrifuge cascade intermittently,' said one Western source familiar with the Iranian programme. 'They simply have not got to the stage where they can run 3,000 centrifuges There is no evidence either that they have been stockpiling low-enriched uranium which could be highly enriched quickly and which would give an idea of a malevolent intent.'
Another source with familiarity with the Iranian programme said: 'Iran has put all this money into this huge hole in the ground at Natanz; it has put a huge amount of money in these P-1 centrifuges, the model rejected by Urenco. It is like the Model T Ford compared to a Prius. That is not to say they will not master the technology eventually, but they are trying to master very challenging technology without access to everything that they require.'